Watch the stars, and from them learn.

If tomorrow were never to come, it would not be worth living today.

The whole of science is nothing more than a refinement of everyday thinking.

The strength of the Constitution lies entirely in the determination of each citizen to defend it. Only if every single citizen feels duty bound to do his share in this defense are the constitutional rights secure.

Humiliation and mental oppression by ignorant and selfish teachers wreak havoc in the youthful mind that can never be undone and often exert a baleful influence in later life.

Whatever there is of God and goodness in the universe, it must work itself out and express itself through us. We cannot stand aside and let God do it.

I have never looked upon ease and happiness as ends in themselves. This ethical basis I call the ideal of the pigsty.